This present invention relates to formwork elements for building purposes and in particular relates to improved interlocking formwork elements of hollow block configuration produced from a hard foam resin material, and adapted to be filled with concrete to provide a rigid wall or the like having high insulating properties.
Elements of this general type are known for forming a hollow wall permanent formwork adapted to be filled with concrete. With these known elements the transverse walls of the blocks are of equal height to the side walls and cross binding of the filled concrete between adjacent blocks is not possible, resulting in a considerable weakening of the concrete wall. In addition the use of horizontal steel reinforcement is not possible and if the transverse members are located inwardly of the ends of the blocks to allow for cross binding of the concrete, special elements are required to enable a corner connection to be made.